Re: [BUG v6.0-rc2] lockdep splat on ct_kernel_enter()

From: gregkh@xxxxxxxxxxxxxxxxxxx
Date: Wed Mar 01 2023 - 07:52:38 EST


On Wed, Mar 01, 2023 at 12:37:29PM +0000, Cheng-Jui Wang (王正睿) wrote:
> On Mon, 2022-08-22 at 16:44 -0400, Steven Rostedt wrote:
> > My tests are failing because of this splat:
> >
> > [ 16.073659] ------------[ cut here ]------------
> > [ 16.074407] bus: 'platform': add driver acpi-ged
> > [ 16.074424] DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())
> > [ 16.074424] WARNING: CPU: 0 PID: 0 at
> > kernel/locking/lockdep.c:5506 check_flags+0x114/0x1d0
>
> > [ 16.074424] lock_is_held_type+0x6f/0x130
> > [ 16.186284] rcu_read_lock_sched_held+0x4a/0x90
> > [ 16.186284] trace_rcu_dyntick+0x3a/0xe0
> > [ 16.186284] ct_kernel_enter.constprop.0+0x66/0xa0
> > [ 16.186284] ct_idle_exit+0xd/0x30
> > [ 16.186284] cpuidle_enter_state+0x28a/0x310
> > [ 16.186284] cpuidle_enter+0x2e/0x50
> > [ 16.186284] do_idle+0x1ec/0x280
>
> Our test in v6.1 stable is failing due to this splat too. The v6.1
> stable kernel still has this splat.
>
> This splat can be fixed by Peter's patch
> https://lore.kernel.org/all/20220608144516.808451191@xxxxxxxxxxxxx/
> , but the fix is part of a big patchset
> https://lore.kernel.org/all/20220608142723.103523089@xxxxxxxxxxxxx/
> introduced in 6.2.
>
> Could the fixes be backported to v6.1 stable?

What "fixes" exactly are you referring to? Can you provide a series of
git commit ids that cleanly apply or better yet, and series of patches
that you have backported and tested to ensure that they work properly?

thanks,

greg k-h